|Sample Type||Volume Required||Minimum Volume||Stability|
|PREFERRED||Serum||1mL||0.5mL||Room Temp.: 7 days
Refrigerated: 7 days
Frozen (-20C): 1 month
Frozen (-80C): 6 months
|ALTERNATIVE||Citrated Plasma||1mL||-||Frozen (-20C): 1 month
Frozen (-80C): 6 months
|REJECTION CRITERIA||Sample contamination; sample compromised|
|STAT TAT||< 24 hours (M-F)|
|STAT TAT Performance||> 90% of results released in 24 hours|
|ROUTINE TAT||< 24 hours (M-F)|
|ALTERNATIVE NAMES||HIT Panel, Heparin-Induced Thrombocytopenia Panel, HIT Screen and Confirm, PF4 with confirmation, Serotonin Release Assay (SRA) equivalent|
|DESCRIPTION||The wp-HIPA (washed platelet heparin-induced platelet activation) test is a quantitative, platelet activation assay capable of detecting clinically significant HIT antibodies. Washed platelet assays, such as the serotonin release assay (SRA) and heparin-induced platelet activation (wp-HIPA) are the reference or GOLD STANDARD methods for diagnosing HIT [1, 4]. Both assays are sensitive and specific for HIT because they ONLY detect antibodies that are capable of activating platelets [1, 3]. The wp-HIPA test is useful in the diagnosis of patients with weakly positive PF4 ELISA results (OD 0.4 – 1.0) and patients with low to intermediate 4T Scores[1, 5]. This test enhances specificity for HIT antibodies by testing 4 concentrations of heparin. This solid-phase ELISA detects the presence of anti-platelet factor 4 (PF4) antibodies in patient serum. Both optical density (OD) and interpretation are reported since OD correlates well with the likelihood of HIT. This test reflexes automatically to the wp-HIPA confirmation assay.|
|NORMAL RANGE||Interpretation: Negative|
1. Linkins LA et al. Treatment and prevention of heparin-induced thrombocytopenia: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012; 141(2 Suppl):e495S-530S.
2. Multz AS et al. The Management of Suspected Heparin-Induced Thrombocytopenia in US Hospitals. Clin Appl Thromb Hemost. 2012; 20(1):68-72.
3. Warkentin TE et al. Laboratory testing for the antibodies that cause heparin-induced thrombocytopenia: how much class do we need? J Lab Clin Med. 200; 146(6):341-346.
4. Hess CN et al. Antithrombotic therapy in heparin-induced thrombocytopenia: guidelines translated for the clinician. J Thromb Thrombolysis. 2012; 34(4):552-561.
5. Cuker A et al. Predictive value of the 4Ts scoring system for heparin-induced thrombocytopenia: a systematic review and meta-analysis. Blood. 2012; 120(20):4160-4167.
|SAMPLE REPORT||Upon request|
|CPT CODE||83520, 86022x3|
|LOINC CODE||73818-7, 50736-8, 77728-4|